1. Field of the Invention
The present invention relates to removable protective caps for writing implements, and in particular, to a removable cap having a passageway to permit air to flow into the interior of the cap and circulate to dry residual ink at the writing point.
2. Discussion of the Prior Art
Removable caps for writing implements are typically configured to enclose the writing portion of the implement to protect the functional components therein. A conventional removable cap usually includes a hollow body member having an opening at one end to receive the implement and being closed at the other end to enclose the writing portion of the instrument within the body member.
Although known removable caps are effective in protecting the functional components of an implement, these caps present several disadvantages. Typically, the conventional removable cap effectively seals the writing point, such sealing thereby preventing the residual ink at the writing point from drying after use. Consequently, seepage of ink from the point commonly occurs. To overcome this difficulty, some known removable caps have been provided with apertures which permit air to flow through the interiors of the caps when the caps are secured on the implements. Examples of such configurations are illustrated in PCT Application WO 89/11978 and in U.S. Pat. Nos. 5,000,604 to Isoda, 5,000,603 to Isoda, and 4,915,529 to List.
PCT Application WO 89/11978 describes a cap for writing instruments having a double end wall and an air channel which perforates the front face of the implement. While there is a path for air flow, the double end wall provides a complex construction requiring close tolerances during construction to prevent obstruction of the vent openings.
Isoda ('603) and Isoda ('604) each describe a safety cap having a cylindrical outer body and a corresponding cylindrical inner cap which is attached to the outer body for sealing the tip of a pen or marker. List ('529) describes a cap body having an axial passageway which is disposed within the cap body and runs parallel to a sealing channel which covers the pen or writing instrument tip.
Although the aforementioned devices provide a passage for air to flow through the interior of the cap, these devices present a number of disadvantages. As made apparent by the foregoing descriptions, they are relatively structurally complex and rely on strategically positioned apertures and/or interconnected spaces to establish the air passageway. Furthermore, many do not provide for circulation of air about the writing tip when the cap is positioned on the writing instrument.
The present invention provides a protective removable cap for a writing implement that effectively engages and protects the writing portion of an implement, while allowing air to circulate about the point to dry residual ink at the writing point. The cap is also configured to allow for circulation of air while preventing contact of the writing point of the implement with the closed end of the cap.